摘要：
select * from a minus select * from b是求A中不存在于B的记录select * from a union select * from b是求A和B的DISTINCT的并集select * from a union all select * from b 是求A和B的冗余并集那么A和B的交集是什么函数来的?交集是 INTERSECT 阅读全文
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摘要：
select * from a minus select * from b是求A中不存在于B的记录select * from a union select * from b是求A和B的DISTINCT的并集select * from a union all select * from b 是求A和B的冗余并集那么A和B的交集是什么函数来的?交集是 INTERSECT 阅读全文
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